U.S. patent number 7,880,883 [Application Number 12/130,798] was granted by the patent office on 2011-02-01 for fluid flow computation, visualization, and analysis.
This patent grant is currently assigned to Interactive Flow Studies Corporation. Invention is credited to Murat Okcay, Bilgehan Uygar Oztekin.
United States Patent |
7,880,883 |
Okcay , et al. |
February 1, 2011 |
Fluid flow computation, visualization, and analysis
Abstract
This document discusses, among other things, systems, devices
and methods for fluid flow analysis for example, in an education
environment. The light source, for example, a laser, is housed to
illuminate particles in a fluid while minimizing exposure to the
user. A control unit is provided that is remote from the fluid flow
device. The fluid flow device further includes a removable fluid
obstacle such that different fluid flow effects can be obtained. A
computational unit is provided to perform computational fluid flow
dynamics analysis on fluid flow models. The computed data can then
be compared to the test data from the fluid flow analysis
device.
Inventors: |
Okcay; Murat (Rochester,
MN), Oztekin; Bilgehan Uygar (Mountain View, CA) |
Assignee: |
Interactive Flow Studies
Corporation (Waterloo, IA)
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Family
ID: |
40293893 |
Appl.
No.: |
12/130,798 |
Filed: |
May 30, 2008 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20090234595 A1 |
Sep 17, 2009 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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11974260 |
Oct 12, 2007 |
7663754 |
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Current U.S.
Class: |
356/432; 702/50;
73/148; 356/342; 356/444 |
Current CPC
Class: |
G01P
5/001 (20130101); G01M 9/067 (20130101); G01M
10/00 (20130101); G01P 5/20 (20130101) |
Current International
Class: |
G01N
21/00 (20060101) |
Field of
Search: |
;356/432-444,336,338,244-246 ;73/148 ;702/50 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Chowdhury; Tarifur R.
Assistant Examiner: Akanbi; Isiaka O
Attorney, Agent or Firm: Clise, Billion & Cyr, P.A.
Clise; Tim
Government Interests
GOVERNMENT SUPPORT
This invention was made with government support from the National
Science Foundation (NSF) under NSF Grant No. IIP-0740550. The
United States Government has certain rights in this invention.
Parent Case Text
RELATED APPLICATION
The present application is a Continuation-In-Part of U.S. patent
application Ser. No. 11/974,260, filed Oct. 12, 2007 now U.S. Pat.
No. 7,663,754, and titled FLUID FLOW VISUALIZATION AND ANALYSIS,
and having the same inventors as the present patent application.
U.S. patent application Ser. No. 11/974,260 is hereby incorporated
by reference in its entirety for any purpose.
Claims
What is claimed is:
1. A fluid flow analysis system, comprising: a computational unit
to perform computational fluid dynamics; a particle image
velocimetry device to generate physical test data at a removable
obstacle, wherein the removable obstacle is positioned in an
imaging portion of a fluid flow path; and a control unit in
communication with the computational unit to receive computational
fluid dynamics data and in communication with the particle image
velocity device to receive the physical test data.
2. The system of claim 1, wherein the computational unit receives
boundary conditions related to a fluid flow path in the particle
image velocimetry device.
3. The system of claim 2, wherein the computational unit downloads
boundary conditions from a server.
4. The system of claim 2, wherein the computational unit downloads
boundary conditions from a user.
5. The system of claim 2, wherein the computational unit downloads
boundary conditions that relate to walls of the fluid flow
path.
6. The system of claim 1, wherein the computational unit generates
mesh data for a given flow model to be modeled in the particle
image velocimetry device.
7. The system of claim 1, wherein the computational unit computes
initial flow conditions based on prior data from the particle image
velocimetry device.
8. The system of claim 1, wherein the computational unit is part of
the control unit.
9. The system of claim 1, wherein the fluid flow path travels
adjacent a light source, which illuminates particles in the fluid,
to cool the light source, wherein the control unit controls a pump,
wherein the obstacle is removable from the imaging portion of a
fluid flow path such that a further obstacle may be positioned in
the imaging portion of a fluid flow path such that a different
obstacle may be studied in the particle image velocimetry
device.
10. A fluid flow analysis system, comprising: a computational unit
to perform computational fluid dynamics; a particle image
velocimetry device to generate physical test data; and a control
unit in communication with the computational unit to receive
computational fluid dynamics data and in communication with the
particle image velocity device to receive the physical test data;
wherein the particle image velocimetry device includes: a housing;
a fluid flow path operably connected to the housing; a pump
connected to the housing and to move fluid in the fluid flow path;
a removable obstacle assembly that includes a portion of the fluid
flow path and a removable obstacle positioned in the portion of the
fluid flow path; a light source to illuminate fluid adjacent the
obstacle in the fluid flow path; an imager to image fluid adjacent
the obstacle in the fluid flow path; and a further control unit in
communication with the imager.
11. The system of claim 10, wherein the further control unit is to
receive commands including at least one of the group consisting of
brightness, exposure, frame rate, gain, and video size, wherein the
imager is a digital, charge coupled device, wherein the housing
includes a blood flow simulation device operably connected to the
fluid flow path, and wherein the housing includes a pressure
measurement device to measure fluid pressure in the fluid flow
path.
12. The system of claim 10, wherein the fluid flow path travels
adjacent the light source to cool the light source.
13. The system of claim 12, wherein the pump runs continuously
while the system is on and provides fluid flow to cool the light
source.
14. The system of claim 10, wherein the obstacle is removable from
the body such that a further obstacle may be positioned in the body
such that a different obstacle may be studied in the particle image
velocimetry device.
15. The system of claim 10, wherein the light source includes a
laser that emits a low power, green light.
16. The system of claim 10, wherein the housing includes a slot to
receive the obstacle assembly, wherein the slot includes an open
end that is not aligned with the light source such that no direct
light escapes the housing with the obstacle assembly removed, and
wherein the light source includes a switch that turns off the light
source with the obstacle assembly removed and that turns on the
light source with the obstacle assembly in the slot.
17. A fluid flow analysis method, comprising: providing
computational fluid flow dynamics data of a fluid flow model
including generating physical test data at a removable obstacle
wherein the removable obstacle is positioned in an imaging portion
of a fluid flow path; performing particle image velocimetry on the
fluid flow model; and comparing particle image velocimetry data to
the computational fluid flow dynamics data.
18. The method of claim 17, wherein providing computational fluid
flow dynamics data includes a user uploading at least one of
boundary conditions or initial conditions for performing
computational fluid flow dynamics analysis.
19. The method of claim 17, wherein providing computational fluid
flow dynamics data includes downloading stored boundary conditions
and initial conditions for computational fluid flow dynamics
analysis.
20. The method of claim 17 wherein providing computational fluid
flow dynamics data includes moving fluid in the fluid flow path
adjacent a removable obstacle assembly that includes a portion of
the fluid flow path and an obstacle positioned in the portion of
the fluid flow path, illuminating fluid adjacent the obstacle in
the fluid flow path, and imaging fluid adjacent the obstacle in the
fluid flow path.
Description
TECHNICAL FIELD
This document pertains generally to fluid flow analysis, and more
particularly, but not by way of limitation, to device, methods and
systems for demonstrating and teaching of fluid flow phenomena.
BACKGROUND
Fluid Dynamics is the study of fluid flow and can be difficult to
conceptualize without laboratory experiments. Particle Image
Velocimetry (PIV) is used to visualize and analyze fluid flow but
particle image velocimetry systems that are used for research are
expensive and utilize Class IV Nd:YAG lasers that may be dangerous,
if appropriate safety measures are not followed, and cost
prohibitive for educational purposes. Examples of particle image
velocimetry systems are described in U.S. Pat. Nos. 6,013,921;
6,549,274; 6,700,652; and 6,940,888.
OVERVIEW
A fluid flow analysis system can include a computational unit to
perform computational fluid dynamics, a particle image velocimetry
device to generate physical test data, and a control unit in
communication with the computational unit to receive computational
fluid dynamics data and in communication with the particle image
velocity device to receive the physical test data. In an
embodiment, the computational unit receives boundary conditions
related to a fluid flow path in the particle image velocimetry
device. In an embodiment, the computational unit downloads boundary
conditions from a server. In an embodiment, the computational unit
downloads boundary conditions from a user. In an embodiment, the
computational unit downloads boundary conditions that relate to
walls of the fluid flow path. In an embodiment, the computational
unit generates mesh data for a given flow model to be modeled in
the particle image velocimetry device. In an embodiment, the
computational unit computes initial flow conditions based on prior
data from the particle image velocimetry device. In an embodiment,
the computational unit is part of the control unit.
The particle image velocimetry device can include a housing; a
fluid flow path operably connected to the housing; a pump connected
to the housing and to move fluid in the fluid flow path; a
removable obstacle assembly that includes a portion of the fluid
flow path and an obstacle positioned in the portion of the fluid
flow path; a light source to illuminate fluid adjacent the obstacle
in the fluid flow path; an imager to image fluid adjacent the
obstacle in the fluid flow path; a further control unit in
communication with the imager, or combinations thereof. In an
embodiment, the further control unit is to receive commands
including at least one of the group consisting of brightness,
exposure, frame rate, gain, and video size. In an embodiment, the
imager is a digital, charge coupled device, wherein the housing
includes a blood flow simulation device operably connected to the
fluid flow path. In an embodiment, the housing includes a pressure
measurement device to measure fluid pressure in the fluid flow
path. In an embodiment. the fluid flow path travels adjacent the
light source to cool the light source. In an embodiment, the pump
runs continuously while the system is on and provides fluid flow to
cool the light source. In an embodiment, the obstacle is removable
from the body such that a further obstacle may be positioned in the
body such that a different obstacle may be studied in the particle
image velocimetry device. In an embodiment, the light source
includes a laser that emits a low power, green light. In an
embodiment, the housing includes a slot to receive the obstacle
assembly, wherein the slot includes an open end that is not aligned
with the light source such that no direct light escapes the housing
with the obstacle assembly removed, and wherein the light source
includes a switch that turns off the light source with the obstacle
assembly removed and that turns on the light source with the
obstacle assembly in the slot.
A method can include providing computational fluid flow dynamics
data of a fluid flow model; performing particle image velocimetry
on the fluid flow model; and comparing particle image velocimetry
data to the computational fluid flow dynamics data. In an
embodiment, the method further includes a user uploading at least
one of boundary conditions or initial conditions for performing
computational fluid flow dynamics analysis. In an embodiment, the
method further includes downloading stored boundary conditions and
initial conditions for computational fluid flow dynamics
analysis.
In an example, a control system for a particle image velocimetry
device is provided that includes a input/output to communicate with
a fluid flow device; a data storage to store fluid flow data; an
imager control module to remotely control operation of an imager in
the fluid flow device; and a display module to output data acquired
from the fluid flow device. In an example, the imager control
device is to control at least one of brightness, exposure, frame
rate, gain, and video size. In an example, the input/output
includes a key that allows operation of the fluid flow device that
can not operate absent the key. In an example, the input/output is
to allow a plurality of users to access a single fluid flow device.
In an example, an analysis module is provided to analyze particle
image velocimetry data. In an example, methods of operating the
present devices and systems are described. A particle image
velocimetry method, includes flowing particle entrained fluid in a
fluid flow path past an obstacle; illuminating the fluid at the
obstacle; imaging fluid flow at the obstacle; optionally replacing
the obstacle with a further obstacle while automatically turning
off the illumination. In an example, replacing the obstacle
includes continuing to flow fluid in the fluid flow path to cool
the light source while replacing the obstacle. In an example,
imaging fluid flow includes remotely controlling imaging and
sending image data to a remote location. In an example, imaging
includes remote display of the image data.
This overview is intended to provide an overview of the subject
matter of the present patent application. Each of the above
examples and the remainder of the present disclosure can be
combined with any other example or disclosure herein. It is not
intended to provide an exclusive or exhaustive explanation of the
invention. The detailed description is included to provide further
information about the subject matter of the present patent
application.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which are not necessarily drawn to scale, like
numerals may describe substantially similar components in different
views. Like numerals having different letter suffixes may represent
different instances of substantially similar components. The
drawings illustrate generally, by way of example, but not by way of
limitation, various embodiments discussed in the present
document.
FIG. 1 is a schematic view of fluid flow analysis system.
FIG. 2 is a view of a fluid flow analysis device.
FIG. 3 is a view of a fluid flow analysis device.
FIG. 4 is a view of a fluid flow analysis device.
FIG. 5 is an enlarged, partial view of a fluid flow analysis
device.
FIG. 6 is a partial view of a flow model assembly.
FIG. 7 is a schematic view of a fluid flow path according to an
embodiment.
FIG. 8A is a view of a flow obstacle insert according to an
embodiment.
FIG. 8B is a view of a flow obstacle insert according to an
embodiment.
FIG. 8C is a view of a flow obstacle insert according to an
embodiment.
FIG. 8D is a view of a flow obstacle insert according to an
embodiment.
FIG. 8E is a view of a flow obstacle insert according to an
embodiment.
FIG. 9 is a view of a control unit.
FIG. 10 is a view of a graphical user interface.
FIG. 11 is a display of data acquired according to an embodiment of
the present invention.
FIGS. 12A and 12B are schematic views of an application of the
present system.
FIG. 13 is a schematic view of an application of the present
system.
FIGS. 14A-14D are schematic views of an application of the present
system.
FIG. 15 is a view of a further embodiment of the flow model
assembly.
FIG. 16 is a schematic view of a computational, visualization, and
analysis system according to an embodiment of the present
invention.
FIG. 17 is a flow chart of a method according to an embodiment.
FIG. 18 is a flow phenomena diagram according to an embodiment.
FIGS. 19-20 are example images produced by embodiment(s).
FIG. 21 is an example computational fluid dynamic, speed flow
shaded plot.
DETAILED DESCRIPTION
The following detailed description includes references to the
accompanying drawings, which form a part of the detailed
description. The drawings show, by way of illustration, specific
embodiments in which the invention may be practiced. These
embodiments, which are also referred to herein as "examples," are
described in enough detail to enable those skilled in the art to
practice the invention. The embodiments may be combined, other
embodiments may be utilized, or structural, logical and electrical
changes may be made without departing from the scope of the present
invention. The following detailed description is, therefore, not to
be taken in a limiting sense, and the scope of the present
invention is defined by the appended claims and their
equivalents.
In this document, the terms "a" or "an" are used, as is common in
patent documents, to include one or more than one. In this
document, the term "or" is used to refer to a nonexclusive or, such
that "A or B" includes "A but not B," "B but not A," and "A and B,"
unless otherwise indicated. Furthermore, all publications, patents,
and patent documents referred to in this document are incorporated
by reference herein in their entirety, as though individually
incorporated by reference. In the event of inconsistent usages
between this document and those documents so incorporated by
reference, the usage in the incorporated reference(s) should be
considered supplementary to that of this document; for
irreconcilable inconsistencies, the usage in this document
controls. Similar elements in different views may be indicated
using the same reference numbers from different views to aid in the
understanding of the present disclosure.
FIG. 1 shows a fluid flow analysis, e.g., a particle image
velocimetry, system 100 that includes a fluid flow device 110, such
as a particle image velocimetry device, connected to a network 115.
The particle image velocimetry device 100 is adapted to take images
of a fluid as it passes an imaging field. Based on images, the flow
speed and direction of the fluid is determined at different parts
of the field. In one use, the system fluid flow analysis 100 is
used in an educational setting to teach students the principals of
fluid flow. The present system 100 is particularly suited for such
a setting as research level particle image velocimetry devices are
too expensive, difficult to use, or pose dangers to the students
that may be unfamiliar with a research level system. The network
115 connects the device 110 to a control unit 120. The network 115
can be a global computer network, such as the internet. In a
further example, the network 115 is an intranet or other local area
network. Control unit 120 includes rule sets to control operation
of the device 110. A user 124 may directly interface with the
control unit 120, for example with an input device such as a
keyboard, mouse, other pointing device, etc. A remote user or users
124 may connect to the control unit 120 through the network 115.
The control unit 120 can include a remote server and data storage.
The control unit 120 can further include algorithms to analyze data
from the device 110. Control unit 120 can further include a display
to display the data in a raw form or an analyzed form. Control unit
120 can further form an automatically configured wireless network
to which users within a certain distance (e.g. inside a
building/lab) may connect, e.g., via wi-fi or Bluetooth enabled
devices such as notebook computers and personal data assistants. In
an example, the control unit 120 is a personal computer that
includes a processor, memory and a web browser to enable
communication with the fluid flow device 110.
System 100 includes a computational unit 130 to provide
computational fluid dynamics (CFD) ability to the present system
100. Computational unit 130 can be a general purpose computer that
includes an operating system and specific CFD software run by the
operating system. Unit 130 may further include additional hardware
that enhances CFD, such as arithmetic logic units, parallel
processor, etc. Unit 130 can further include various computer
networking devices that allow it to communicate via the network 115
to the control unit 120 and, if needed, to remote users 126. In a
further embodiment, the computational unit is a sub-system of
control unit 120. The computational unit 130 is to use numerical
methods to simulate and predict various flow properties under model
and initial conditions. Such models and conditions can include
laminar flow and two-dimension modeling. Further discussion of CFD
and operation of computation unit 130 is found below.
System 100 can further include an interactive fluid flow server
140, which can provide control software for the fluid flow device
110 to the control unit 120, provide communication links between
the control unit 120, remote users 126, if any, and the
computational unit 130. Server 140 can also provide data files for
computational unit 130.
In operation, the fluid flow device 110 takes images of fluid flow,
e.g., with entrained particles, based on control signals from the
control unit 120. These images are sent to the control unit 120 via
a direct link, e.g., a firewire cable, or via network 115. The
control unit 120 analyzes the image data to provide a fluid flow
data. This data may be presented as a visual representation or as
raw data. Raw data can include numerical data. The visual
representation can play an important role in teaching fluid
dynamics to students. The user 124 or 126 may change certain
operational parameters of the fluid flow device 110 to improve the
capture of data or alter the flow being analyzed.
FIG. 2 shows a schematic view of a fluid flow device 110 according
to an embodiment. The device 110 includes a housing 203 to support
a pump 205, a fluid reservoir 207, and an obstacle insert 210. The
housing encloses all of these elements in an embodiment of the
present invention. A fluid flow path 212 fluidly connects the pump
205, reservoir 207, and obstacle insert assembly 210. The fluid
flow path 212 is mostly enclosed within the housing 203. In an
embodiment a relatively short portion of the fluid flow path can
extend outside the housing 203. In an embodiment, the fluid in the
path is water. A light source 220 is positioned in the housing and
illuminates the fluid flow path 212 at the obstacle insert assembly
210 such that the fluid and any entrained particles are visible. An
imager 225 is positioned in the housing and images the fluid at the
obstacle insert assembly. In an embodiment, the imager 225 takes
pictures of the fluid covering the areas before, at, and after the
obstacle insert assembly. The obstacle insert assembly 210 is
adapted to change the obstacle in the fluid flow path at the field
where the light source 220 illuminates the fluid and the imager 225
can image the illuminated fluid at this field. A power source 230
provides electrical power to the pump 205, light source 220, and
the imager 225. The power source 230 can include a battery or
circuitry to receive standard utility power and output a DC power
signal. In an embodiment, the power source 230 outputs different
power signals to the pump, light source, and imager. For example,
the pump 205 may require a power signal of about 12 volts and 2
amps (max.). The light source may require a power signal of 3 volts
and 0.3 amp (max.). An input/output ("I/O") 235 is connected to
housing 203. The I/O 235 is serial connection, modem, firewire,
i.e., IEEE 1394, wireless, IEEE 802.016 connection, or other such
connection to a further electronic device such as network 115 or
control unit 120 as shown in FIG. 1. The I/O 235 can input control
signals to at least one of the light source 220, imager 225, and
pump 205. The I/O 235 can also output the image data from the
imager to the control unit, e.g., control unit 120 as shown in FIG.
1. The I/O 235 can further include a key and keyhole, i.e., a
mechanical key system, or be adapted to receive an electronic key
to enable or disable the fluid flow device 110.
In an option, a control unit 240 is positioned in the housing 203.
This control unit 240 can be in communication with at least the
imager and, if desired, with the pump 205 and light source 220, to
set default operational parameters of at least one of these
devices. The control unit 240 may further include memory to store
data from the imager 225. The control unit 240 can further control
operation of the input/output 235.
FIG. 3 shows an external view of an embodiment of the fluid flow
analysis device 110. Device 110 includes a box-like housing 301
with a connected lid 303 to create a closed internal space to hold
the operating parts therein. The housing 301 is formed of a rigid,
opaque material, such as metal or plastic. The front face 305 of
housing 301 includes an indicator light 307 to show whether the
device 110 is on or off, i.e., powered or unpowered. A fluid flow
control knob 309 extends from the front face 305. This knob 309
operates a fluid flow variable valve, which is fluidly connected to
a fluid flow path, to increase and decrease the speed of fluid flow
in the fluid flow path within the device. In a further embodiment,
an electro-mechanical actuator, not shown, is provided with the
housing to control fluid flow in place of the manual fluid flow
valve. Such an actuator would be controlled by control signals from
the control unit to control the fluid flow rate. The flow model
assembly 310 is received in a slot in the front face 305 of housing
301. The slot includes an open end in the housing. The open end is
not aligned with the light source such that no direct light escapes
the housing with the obstacle assembly removed. Assembly 310 can be
releasably held in the fully inserted position by ball and detent
mechanism or by magnets. The fluid flow path further extends out of
the front face 305 via elbow connectors 313, transparent tubing 315
and releasable connectors 317. The releasable connectors 317 are
fluid tight when removed from mating connectors of the flow model
assembly 310. These releasable connectors 317 allow for the removal
of the flow model assembly 310 with the device 101 powered in the
on state. The connectors 317 are released and the flow model
assembly 310 is removed from the housing 301 such the obstacle
insert in the flow model assembly can be changed.
The lid 303 includes apertures such that the fluid flow path
extends outside the lid. A large aperture 321 is provided above a
fluid reservoir that is within the housing. A reservoir cover 323
is visible through the aperture 321 and can be removed without
removing the lid 303 such that additional fluid can be added to the
reservoir without stopping the device 101. Lid 303 is fixed to the
open top of the housing 301 such that access to the parts therein
is not easily attained. However, access to the flow model assembly
and the fluid is easily attained. This allows a relatively
inexperienced user to use the device with a reduced chance the user
will damage the device or injure themselves.
FIG. 4 shows a view of fluid flow analysis device 110, which
includes pump 205, reservoir 207, obstacle insert 210, for example,
fluid flow model 310, light source 220, imager 225, and power
source 230. An input/output is not shown. Moreover, fixed portions
of the fluid flow path, including the elbows 313 and connectors
317, are shown. The fluid flow path will be described in greater
detail elsewhere in this document. The pump 205 includes an inlet
411 and an outlet 413. Inlet 411 is in fluid communication with the
fluid reservoir 207. Outlet 413 exits pressurized fluid from pump
205. That is the pump creates a pressure head in the fluid at the
outlet, which causes the fluid to flow in the path. A damping
system 415 connects the pump 205 to the box 301. The damping system
415 includes at least one and, in an embodiment, a plurality of
structures to reduce the vibration and noise caused by the pump.
Such vibration may alter the results of the fluid flow analysis.
The vibration reduction structures can include a polymer spacer
block intermediate a wall of the box and the pump. A plurality of
rigid, vibration damping washers are staked intermediate a
plurality of soft, polymer O-rings to further dampen vibrations
from the pump to the housing wall of the box. A plastic bolt and
nut are used to fix the pump to the sidewall of the housing. In an
embodiment, O-rings are positioned on the interior and exterior of
the sidewall. Washers are positioned outwardly of the O-rings. A
damping jacket may wrap around the outer surface of the pump to
further dampen vibrations and reduce noise. A pump will have a
certain level of vibration due to its pumping action. The damping
system will reduce the level of vibration so as to not interfere
with the fluid flow analysis. The damping system will also reduce
pump noise.
As vibration may adversely effect the operation of the particle
image velocimetry device, its housing 301 can include vibration
damping feet. The feet can be rubberized feet in an example. The
feet may also assist in noise reduction.
The fluid flow obstacle insert assembly 210 includes a base 431 to
support an intermediate member 433 that defines a portion of the
fluid flow path, and a cover 435. The intermediate member 433 is
transparent to the light from the light source such that the light
illuminates the fluid flow path in the intermediate member. The
intermediate member 435 includes two fluid ports at a front face.
The ports extend outwardly of a front face of the housing when the
insert assembly 210 is positioned in the housing. A face plate 439
is fixed to the front of the stack of the base 431, intermediate
member 433, and cover 435. The face plate covers the aperture in
the front wall of the housing to assist in preventing light from
escaping the housing. In an embodiment, the ports fix the face
plate to the intermediate member. The cover 435 is removably
secured to the top of the intermediate member. Removal of the cover
435 gives access to the obstacle insert. The cover 435 fluidly
seals the fluid flow path in the intermediate member 433. An
aperture 437 that acts as a viewing window for the portion of the
fluid flow path in the intermediate member is positioned in the
cover 435. In an embodiment, the aperture 437 is aligned with the
portion of the fluid flow path that includes the obstacle
insert.
The light source 220 is fixed adjacent one sidewall of housing 301.
The light source 220 includes an emitter 421 to output light toward
the fluid flow insert 310. The emitter 421 can be a light emitting
diode in an example. The emitter can be a laser in an embodiment.
In an embodiment, the light emitted by the light source is a green
light. In an embodiment, the light emitted is a red light. The
laser can be a category II, line laser that emits light at about
532 nm. While illustrated as a single light source, it will be
recognized that a further light source can be mounted in the
housing. The only requirement of the light source is that it
illuminate particles in the fluid and be visible to the imager. In
an embodiment, the light source emits green light or red light or a
combination thereof. In an embodiment, the further light source
could be mounted orthogonal to the light source 220. This will
reduce edge effects at the flow model insert. The emitter 421 is
mounted to a block 423. In an embodiment, thermal paste is applied
at the interface between the emitter and the mounting block. The
mounting block 423 is fixed to the housing and includes a portion
of the fluid flow path through the block or mounted to the block.
The mounting block can include an elongate support that is fixed to
a main body of the block via a damper, such as an o-ring, to dampen
effects of shock during movement of the fluid flow device to thus
protect the light source from damage. As a result, the fluid flow
will cool the block 423, which in turn will cool the emitter 421 to
assist in operation of the emitter and prolong its life.
An electrical junction 440 is fixed to the housing 301. The
electrical junction 440 electrically connects the electrical
components of the device 110 together. The junction 440 is
connected to power source 230 and distributes power to at least the
pump 205 and light source 220. The electrical junction may power
the imager 225 as well. In another example, the imager is powered
through its communication connection, for example, through a
universal serial bus (USB) or firewire connection. The junction 440
may further act as a communication junction between the imager and
a remote terminal, such as the control unit 120.
The imager 225 includes a mount 450 and the imager device (not
shown in FIG. 4). The mount 450 includes a plurality of support
posts 452 that are fixed to the housing lid. In an embodiment, the
posts are cantilevered from the housing lid. These support posts
extend inwardly into the interior of the housing aligned with the
aperture 437 of the obstacle insert assembly 210. A support
platform or board, such as a printed circuit board (PCB), 454 is
fixed to the ends of the support posts 452. Platform 454 can act as
support for an imaging chip. An imaging device, such as a charge
coupled device, is fixed to the bottom of the platform 454. The
lens of the imaging device is aligned and closely adjacent the
aperture 437 such that the imaging device can receive reflected
light from the fluid flow path at the obstacle insert.
The imaging device is a high resolution, black and white camera in
an embodiment. In a further example, the imaging device is a color
camera. The camera can be a digital camera. The camera can include
charge coupled devices. The imaging device may further provide
raster scanning. The color camera may be used to study a fluid
mixing of fluids that have different colors. For example, a first
unit of water colored with a first dye and a second unit of water
colored with a second dye can be imaged by the color imager at the
imaging area. In a further example, the imager can image two
different fluids that may have different flow properties and
different colors. The imager may be adapted to sense and output
pseudo-color image data that can be enhanced or manipulated in the
control unit or locally with the device 110 to produce a color
presentation of the fluid flow.
A switch 470 is positioned at the rearward end of the flow model
assembly 310. The switch 470 is in an "on" position with the flow
model assembly 310 fully inserted into the slot in the housing 301.
The switch 470 in the "on" position allows power to the light
source 220 and full power to the pump 205. When the flow model
assembly 310 is slid outwardly of the housing, then the switch 470
moves to its default, "off" position. The switch 470 in the "off"
position turns off the power to the light source. The switch in the
"off" position turns off the full power connection and allows for a
reduced power to the pump. The pump will continue to move fluid
through the fluid flow path in this reduced power state but at a
reduced pressure or reduced volume. In one embodiment, the pump
will continue to move fluid to cool the light source even with the
light source off.
FIG. 5 shows an enlarged perspective, partial view of the fluid
flow device 110. In this view, the imager 225 is shown with the
lower part of the support posts 452 and the support platform 454.
On the bottom side of the platform 454 is the imaging device 550,
which includes a lens system focused on a portion of the fluid flow
path 555 that is directly below the aperture 437 and in which is
positioned a fluid flow obstacle 800. Details of the fluid flow
obstacle 800 will be described in greater detail with regard to
FIGS. 8A-8E. A connector unit 560 includes a bolt 561 extending
through the base 431, intermediate member 433, and cover 437 and a
fastener, such as a wing nut, 563 to removable hold the base 431,
intermediate member 433, and cover 437 together. The base 431 and
intermediate member 433 include a translucent portion and may be
supported by a rigid backing, for example, a metal plate. The rigid
backing ensures that the seal, e.g., o-ring or gasket, that seals
the fluid flow path in the obstacle insert assembly 210 has an
even, fluid-tight seal. The obstacle insert 800 sits in a recess in
the intermediate member 433 such that the base portion 805 is not
in the fluid flow path 570 and the obstacle 810 is in the fluid
flow path. The recess in the intermediate member 433 has a depth
essentially equal to the height of the base of the obstacle insert
800. The flow model bolt 561 and slot on the bottom of the housing
301 act as a guide to the flow model assembly 310. The bolt head is
slightly larger than the slot width which allows the flow model
assembly 310 to glide into the slot but prevent it from lifting up,
which securely locates the flow model assembly 310 in the slot.
FIG. 6 shows an enlarged, partial view of the obstacle insert 210
with the cover 435 removed from the intermediate member 433 to show
the fluid flow path 570 and obstacle insert 800 therein. The bottom
surface of the fluid flow path is essentially co-planar including
the top surface of the obstacle insert base 805. The smooth-walled,
gradually turned fluid flow path in the obstacle insert 210 allows
the fluid flow to develop gradually and to be relatively uniform
before the obstacle 800 is encountered. The fluid flow in one of
the ports (not shown) and travels past the obstacle insert 800,
which creates a fluid flow pattern based on the type and shape of
obstacle 810. The imager 225 takes an image of the fluid at the
obstacle 810 for purposes of education and study of fluid flow
dynamics in an embodiment.
The housing, insert, imager position, and flow path are all
selected to minimize the effect of gravity on the particles in the
fluid flow path. This corrects for one source of error in the study
of fluid flow dynamics when using system 100. For example and with
reference to FIGS. 4-6 the gravitational effects will be in the
z-axis. The imager is taking images of the fluid flow with the path
in the x-y plane, thus the gravitational effect is minimized. The
fluid flow can be analyzed using particle image velocimetry
techniques. The fluid is seeded with particles. The particles are
selected to have minimum impact on fluid flow and maximize the
contrast with the background and fluid. Ideally the particles will
have essentially a neutral buoyancy relative to the fluid in the
flow path.
FIG. 7 shows a schematic view of the fluid flow path 701 within the
device 110. Path 701 includes a plurality of tubing sections, at
least some of which is transparent such that some indirect
illumination of the fluid is visible, for example, outside the
housing to indicate to a user that the light source is working.
This also allows visual inspection of potential bubbles in the
system and helps in removing them via the syringe. A plurality of
fluid connectors join the tubing sections. The connectors may be
opaque. While not drawn to scale, the tubing lengths as shown
represent lengths relative to other lengths of tubing. Beginning at
the pump 205, an outlet 705 connects to tubing 707 that inputs into
a tee-connector 709. One leg 711 of the tee 709 connects through
tubing 711 to the light source 220. The fluid flowing in this path
will cool the light source 220. An outlet 713 of light source 220
connects to tee-connector 715. A leg of t-connector 715 connects to
tubing 717 that outlets outside a top of the housing and enters
reservoir 207. Reservoir 207 is in fluid communication with a
further port that connects to tubing 719 that connects to an elbow
721. A leg 723 of tee-connector 725 is fluidly connected to the
elbow 721. A leg 727 of tee-connector 725 connects to the pump 205.
The preceding represents a cooling fluid flow path. A feed-back
path is also provided. The feed-back path includes a second leg 731
of tee connector 709 that fluidly connects with tee-connector 733.
A leg 735 of tee-connector 733 fluidly connects with a flow reducer
737 that connects with a reduced diameter tube 739. At the other
end of the tube 739 is a reducer 741 that fluidly connects with a
leg 743 of tee-connector 725 to complete the fluid circuit. The
reduced diameter tube 739 and reducers 737, 741 restrict the volume
of fluid flow through the feed-back path. If the obstacle assembly
is removed, then the fluid can still flow through the feed-back
path with the pump at a reduced power setting.
Faster flow allows fluid streamline visualization, which is very
important in understanding fluid flow phenomena. Slow flow allows
particle image velocimetry analysis to be performed allowing the
calculation of velocity and direction of the fluid flow. Once fluid
velocity is calculated other flow parameters such as voracity,
shear stress, shear strain can be calculated. Such visualization
and calculation can be performed in the control unit 120 or in the
remote user locations 126.
The fluid flow imaging portion 760 of the fluid flow path 701 is
now described. A further leg 761 of tee-connector 733 fluidly
connects to an elbow 763, which in turn fluidly connects to a
variable flow resistor, e.g., a variable valve, 765 controlled by
manual knob 309. The user can increase/decrease fluid flow by
activation of knob 309, which in turn opens and closes the fluid
flow path at flow resistor 765. Flow resistor 765 fluidly connects
to a port 313 and an exterior tube 315. Tube 315 connects to port
317, that connects to the portion of fluid flow path in the
obstacle insert assembly 210. A further port 317 exits the assembly
210 at the front of the housing and fluidly connects to a tube 315.
A second port 313 connects to tube 315 and reenters the housing. A
further tubing 771 connects to leg 773 through an elbow 775 and
tube 777.
The fluid typically flows in the direction shown and described
above. If it is desired to reverse fluid flow, then one of the
connections to the reservoir 207 is released. The fluid flow
automatically reverses direction based on the connections shown and
need to continually circulate fluid to cool the light source. The
fluid flow may also be reversed by insertion of a valve to block
fluid flow. In an example, such a valve may be placed in tube that
is closely adjacent the reservoir, such as tube 717, 719 or in
place of connector 721. Other positions of such a valve are within
the scope of the present disclosure.
The fluid flow path is configured to allow fluid to flow even with
the reservoir 205 removed from the fluid flow path. The reservoir
205, may be removed from the path when further fluid is added to
the reservoir or seed particles are added to the reservoir, for
example. Such continuous fluid flow cools the light source and does
not require the pump to be turned off when the reservoir is
accessed by the user.
Fluid flow measurement devices 791, 793 are optionally connected to
the at least one and preferably separate portions of the fluid flow
path. In an embodiment, at least one fluid flow measurement device
791 or 793 is fluidly connected to a tubing outside the housing.
The FIG. 7 illustrated embodiment shows the measurement device 791
in tubing 315 on the right and the measurement device 793 in
separate tubing 315 on the left. As a result, one of the fluid flow
measurement device 791, 793 is on the inlet side of the obstacle
insert 210 and the other is on the outlet side of the obstacle
insert. It will be recognized that either measurement device can be
placed elsewhere in the fluid flow path. The measurement devices
791, 793 can be pressure transducers to measure the fluid pressure
at the location in the fluid flow path. For example, in the
illustrated example, the devices 791, 793 can measure the pressure
differential across the obstacle insert 210 at a certain flow rate.
The devices 791, 793 can further include flow rate sensors to
determine flow rate. As a result, the pressure drop across the
obstacle insert at a measured flow rate can be measured. In
operation, a user can measure the pressure and flow rate absent an
obstacle in the insert 210. An obstacle is then placed in the
insert 210 and a second measurement is taken. From this the
pressure drop due to the obstacle can be calculated, i.e., the
difference between the no-obstacle measurement and the obstacle
measurement. The measurement devices 791, 793 can further be
connected to the I/O of the fluid flow device 110 such that the
data measured can be stored or sent to the remote users and control
unit. Thus, this data can be correlated to the fluid flow image
data taken by the imager.
The fluid flow path and the elements that define the fluid flow
path are adapted to fluidly confine and allow the flow of different
types of liquids. Accordingly, different types of liquid can be
analyzed and studied. In an example, different transparent fluids
with different viscosities can be used to study different Reynolds
numbers, e.g., inertial forces/viscous forces. Such study can teach
students the difference between laminar flow and turbulent
flow.
FIGS. 8A-8E show various embodiments of a fluid flow obstacle
insert 800. The description of the common features of insert is
shown in FIGS. 8A-8E with use reference numbers absent any
alphabetic suffix. Discussions of individual insert with use an
alphabetic suffix that corresponds to the figure. Insert 800
includes a base 805 that supports a shaped obstacle 810 upstanding
from an upper surface of the base 805. Base 805 is shaped generally
like a rectangular prism with a volume that is only slightly
smaller than the recess in the base of obstacle assembly. Other
shapes are also within the scope of the present disclosure such as
equilateral shapes, e.g., equilateral triangular prisms. The base
805 includes a height such that it is essentially co-planar with
the lower surface of the fluid flow path in the obstacle assembly.
This results in the base having little effect on the fluid flow in
the fluid flow path. The base 805 may further indicate the field of
view of the imager so that the user will know the intended view.
The obstacle 810 on the other hand extends outwardly, as shown
upwardly, from the base 805. The obstacle 810 is intended to be
directly in the flow path with the base 805 inserted in the recess
of the obstacle assembly base. The obstacle 810 will cause the
fluid in the fluid flow path to alter course and as a result cause
fluid to demonstrate various important aspects of flow phenomena,
such as rotational flow, flow separation, turbulence, flow
interaction with boundaries, etc. The use of different obstacles
will thus be a learning tool for a student studying various fluid
flow phenomena. The base 805 being equilateral results in the
obstacle 810 being placed with any side toward the incoming flow.
Non-equilateral obstacles can also be used with various embodiments
of the present invention. The obstacles can be of any shape of
interest to demonstrate fluid flow phenomena. The obstacles can
further be mounted such that they move on the base in response to
fluid flow. In an example, the obstacle is a pinwheel or waterwheel
shape that will rotate as the fluid flows past the obstacle. In a
further example, the resistance to rotation can be adjusted. For
example, a nut could be tightened on a bolt that secured the
movable obstacle on the base. Thus, the user can adjust the freedom
of movement of the obstacle. The orientation of the obstacle can
also be changed and the bolt can be fully tightened making the
obstacle immovable at a fixed orientation. Accordingly, each of the
obstacles 800 of FIGS. 8A-8E can provide four different flow
obstacles based on their orientation in the recess. For example,
the obstacle 810A of FIG. 8A has a three dimensional shape with a
triangular cross section. The hypotenuse side surface can face the
inflow of fluid such that the user can view, sample, and study the
affects of fluid flow striking this surface and flowing around a
vertex side and a short flat side with the long flat side facing
the outflow of fluid. The entire obstacle 800A can be turned such
that the short flat side faces the inflow of fluid by simply
removing the insert assembly, opening the assembly, lifting the
insert, rotating the insert, replacing the insert, closing the
assembly, and reinserting the assembly into the fluid flow device.
In general, the number of different fluid flow paradigms each inert
800 represents is determined by the number of sides of the base
805.
The inserts can be transparent (for example made from acrylic or
other clear polymer) allowing light to pass through the obstruction
and illuminate the fluid on the other side of the obstruction. This
will allow student user to observe fluid flow all around an
obstacle, such as a complete cylinder, aerofoil or other obstacle
shapes. Depending on the number and position of light sources, some
orientations may be preferable (obstacle may block the light source
to some of the particles depending on orientation, or in the case
of transparent obstacles, may bend the light and may potentially
produce artifacts in the image). The inserts are designed in a way
such that at least one orientation will minimize such effects. The
translucent parts in the flow model assembly are reinforced with
metal plates to ensure an even seal on an o-ring in the flow model
assembly, in an embodiment. These plates also ensure robustness of
the flow model assembly and create a good seal, otherwise uniform
pressure is not applied and the fluid may leak
Each of the obstacles 805B-805E will now be discussed.
Obstacle 805B includes base 805, which is the same for all
obstacles so that the base fits the recess in the intermediate
member of the obstacle assembly 210. The obstacle 810B includes an
upstanding solid geometric structure with three straight, flat and
planar sides, a fourth concavely curved side surface. The top
surface is flat to mate and possibly fluidly seal against the cover
435 of obstacle assembly 210.
Obstacle 805C includes base 805 and an obstacle 810C that includes
three flat, planar sides (with two the same length and the third
significantly shorter). A fourth side opposite the short side is
convex.
Obstacle 805D includes base 805 and a rectangular prism obstacle
805D. None of the sides of the prism are the same length.
Obstacle 805E is a triangular prism that is offset from toward the
leftward side of its base 805E with one leg 831 of the triangle
being longer than the others 832, 833. Leg 832 is positioned
adjacent one side of the base 805E. The vertex of sides 831, 833 is
positioned at about the center of base 805E.
Other obstacles can also be used. These other obstacles can place a
flexible plate in the fluid flow path. Such a plate can be moved on
the fluid flow. The plate may further be cantilevered such that one
end of free to move based on the forces of the fluid flow. Other
obstacles can simulate airplane wings or hydrofoils. Still other
obstacles can simulate a nozzle, a throat, or a diffuser. The flow
separation phenomena can be studied very well with the present
system 1000 by using various flow models and by varying the speed
of the flow the separation effects can be observed visually. The
flow models, i.e., inserts with obstacles, can model a nozzle, a
throat, or a diffuser. The obstacle portion of the insert would
follow the shape of the top and bottom edge of the diagram shown in
FIG. 18. The flow phenomena that we can observe can be summarized
in the diagram shown in FIG. 18. It will be recognized that the
insert need not include each of these different flow structures.
The boundary layers, velocity, and pressure gradients for each of
these flow structures can be studied, imaged, visualized, and
calculated. See for example, "Mechanics of Fluids," B. S. Massey,
Chapman & Hall, ISN 0 412 34280 4 and "Fluid Mechanics," Frank
M. White, McGraw-Hill Book Company, ISBN 0 07 069673X, hereby
incorporated by reference.
Flow separation occurs because of excessive momentum loss in the
boundary layer near a wall. This loss can be initiated by an
adverse pressure gradient where dp/dx>O. Flow separation can
occur in a diffuser or a sudden expansion. In the diffuser flow
separation will occur at one or both walls if the diffuser angle is
too large leading to excessive adverse pressure gradient. Flow
separation will result in reverse flow, increased losses and poor
pressure recovery. This is called a diffuser stall. In a favorable
pressure gradient--like in a nozzle--where dp/dx<O flow
separation can never occur. Separation occurs when
.delta.u/.delta.y=0 (or .tau..sub.w=O) where .tau..sub.w is the
wall shear stress. The boundary layer may become turbulent once the
laminar layer separates. Separation streamline is the line of zero
velocity dividing the forward and reverse flow, and it starts from
the separation point. The reverse flow causes large irregular
eddies. These eddies are undesirable because of energy loss. The
separated boundary layer curls, and the disturbed flow region
continues downstream. The imager can clearly image these effects
and provide the data to multiple users as described herein. The
pressure downstream remains approximately the same as at the
separation point because the energy is dissipated as heat.
Both laminar and turbulent boundary layers separate, but laminar
layers tend to separate more easily. This is because the laminar
flow velocity gradient from the wall is lower and the adverse
pressure gradient can more rapidly halt the slow moving fluid near
the wall, e.g., the wall of the fluid flow path or tubes described
herein. A turbulent boundary layer is more resistant to adverse
pressure gradient. However, greater the adverse pressure gradient
quicker the separation for both laminar and turbulent flows. The
boundary layer, .delta.(x), thickens rapidly in an adverse pressure
gradient, and one can no longer assume that .delta.(x) is small.
The boundary layer separation greatly affects the flow as a whole.
A wake of disturbed flow downstream is formed which radically
alters the flow pattern. Such a wake can be imaged and displayed to
users according to the teachings herein. The effective boundary of
the flow is an unknown shape--which also includes the zone of
separation--instead of the wall. The altered flow pattern may cause
the position of the minimum pressure to move upstream. This may
result in the point of separation moving upstream. Flow separation
becomes very important in the design of aerodynamics. For example,
flow separation increases drag in racing cars or airplanes. The
present system can further image flow separation caused by sharp
edges that can be studied by the user.
Still other obstacles can include variously shaped recesses in the
obstacle insert. Examples of recesses include any upstanding shape
described herein, but recessed into the upper surface of the
obstacle body.
FIG. 9 is a view of a control unit 120 remote from the fluid
analysis device 110. The control unit is to receive data from the
device 110 and instructions from the users. This data can be
transmitted wirelessly or over a wired network. At times using this
received data and instructions, the control unit sends control
signals to the fluid flow analysis device 110. The control unit 120
can be a server with appropriate storage and rule sets. The control
unit 120 depicted in FIG. 9 includes an input/output module 910
that provides communication between modules in the unit 120 and
outside devices, such as communication over networks to the fluid
flow device 110. In particular, the I/O module 910 is adapted to
receive image data from the imager. The I/O module 910 may further
include data transfer devices such as a universal serial bus,
serial bus, disk drives, or further global computer connections
such as the Internet. The I/O module 910 may further include a
network interface device is to provide connectivity between the
control unit to a network using any suitable communications
protocol. Examples of communications protocols include wireless
protocols such as Institute of Electrical and Electronics Engineers
(IEEE) 802.11a/b/g/h and IEEE 802.16., Ethernet IEEE 802.3x,
TCP/IP, and the like. The network can be the Internet, an intranet,
a local area network (LAN), a wide area network (WAN), and a
cellular network based on GSM and TDMA, as examples. It will be
recognized that the I/O module may connect to one type of network
or any number of networks of the same or different types. If a
standard network is used, it will further be recognized that the
I/O module may further utilize network browsers such as Internet
Explorer, Mozilla, Opera, etc. and may use a standard operating
system such as GNU/Linux, MS-Windows, or Mac-OS. The I/O 910 may
further provide a digital key to the fluid flow device I/O 235 to
allow operation of the fluid flow device 110. The I/O module 910 is
further adapted to provide communication with a plurality of users.
A group of users may be using the same fluid flow device. This will
be helpful for group projects and labs in undergraduate coursework.
A group of users may each individually be using separate fluid flow
devices using a same control unit. This will allow a central
control unit to control a plurality of fluid flow devices to
centralize programming and provide improved updating and
troubleshooting of the control unit. This can also allow a
professor to stage example of principals of fluid dynamics being
studied and show the students actual, an possibly real-time, fluid
flow examples, whether or not the students are remote.
Control unit 120 further includes data storage 920 to store raw
data from the fluid flow device, to store control parameters at the
time of producing the raw data, and to store analyzed data that has
been processed according to fluid flow dynamics. An analysis module
930 is provided to apply the analysis rule sets to the data stored
in the data storage 920. The analysis module can perform particle
image velocimetry analysis. The module may further operate and the
data to add color to the images generated by the data. A default
rule set 935 is stored in the control unit 120. The default rule
set 935 includes the base control parameters for control of the
fluid flow device 110 and the login in requirements for users, such
as students, to access the control unit and hence the fluid flow
device 110.
An imager control module 940 is provided to control the imager in
the fluid flow device. The imager control module 940 will store the
parameters for the particular imager in the fluid flow device 110.
The imager control module 940 will further allow the users to
change certain parameters to improve the results of the fluid flow
analysis. Examples of such parameters are brightness, exposure,
gain, etc.
The control unit 120 further includes a display module 950. The
display module 950 can present the images and videos from the fluid
flow device in essentially real-time such that a data collection
period can begin after the user can see that the system 100 is
working and good data can be acquired. Further, the display module
950 can provide a user friendly and familiar interface between the
hardware and software of the system 100 and a novice user. This
will aid in use of the present system as a teaching tool. The
display module 950 and other modules can be used via a user
friendly interface, such as a web browser.
The above modules may reside in a single computer, or can be
distributed across multiple computers connected via a network or a
bus. A plurality of user interfaces or front-end servers may
receive requests and communicate with appropriate modules, and
forward back their replies. Front-end servers may connect to
plurality of controllers which then can be connected to plurality
of devices. A plurality of analysis servers or storage servers may
also be used.
Fluid flow device and the controller device may be merged. The
controller device may be embedded within the body of the fluid flow
device and connected to the camera internally.
FIG. 10 is a view of a graphical user interface 1000 that may be
used with the control unit. The graphical user interface (GUI) 1000
provides display of graphics including symbols, interactive buttons
or fields, data displays and other representations to a user. GUI
1000 can be remote from the fluid flow device and communicate to
the elements of the fluid flow device through a communication
channel, e.g. as described herein. GUI 1000 provides a user
friendly device to allow the user to control operation of the fluid
flow device and acquire fluid flow data. GUI 1000 includes an
imager control 1010 and a fluid flow data preview 1030. Imager
control 1010 includes a plurality of control settings 1011 for the
imager. These control settings 1011 include by way of example, but
are not limited to, brightness 1012, exposure 1013, gain 1014,
frames 1015, and video size 1016. Brightness 1012 controls the
overall brightness of the image acquired by the imager. In an
embodiment, brightness is set to a medium-high value for
visualization (i.e, for a preview image), and to a medium-low value
for actual data acquisition in particle image velocimetry. In some
setups, artifacts such as small bubbles stuck to various surfaces
may be present. To correct for such artifacts, the seed particles
are chosen to be brighter than the artifacts. The user can use the
present GUI 1000 to lower brightness (and adjust gain and exposure)
to a point where the seed particles imaged brighter than the
artifacts such that the remaining artifacts are not imaged or the
not outside general data errors. Generally, for PIV, it is
desirable to have bright particles with high contrast from the
background. Ideally, everything other than the particle seeds are
as dark as possible. Exposure 1013 controls the time the image
sensors are going to be exposed per frame. If this value is high,
sensors are going to be exposed longer, resulting in longer
streamline effects as the particle seeds being imaged are moving.
For PIV analysis, exposure is as low as possible to obtain a fast
snapshot of the particle seeds as points rather than streamlines.
However, when exposure is low, fewer photons hit the image sensors
in the duration allocated per frame (i.e., exposed to photons), so
the particle seeds will appear dimmer. One way to compensate for
the dimmer particle seed images is to increase the gain. Gain 1014
controls how sensitive the image sensors are per unit time.
Increasing gain amplifies the image data. However, increasing gain
also increases the noise in the signal, and hence in the data.
Frames 1015 controls the number of frames that will be captured in
an individual data acquisition session. It is desirable to keep
this value low when adjusting the settings for fast response, and
set this value to a higher value when the settings are
satisfactory. Video size 1016 controls the scaling factor for the
purpose of generating a video image. For fast experimentation, it
may be preferable to reduce the size to 50% or 25% and increase it
when the optimal parameters are found. This is to control the size
of the visible image, such as that shown in the preview 1030. The
acquired PIV data need not be affected by this setting as the data
is always available full-size. Smaller video image sizes are useful
to reduce latency experienced by users during heavy network traffic
periods or with users having low bandwidth connections
The settings 1011 can further include user manipulatable fields
1021, 1022, 1023, which allow that user to change the settings. As
shown, each of the control settings 1012-1016 each includes three
fields. However, three fields may not be required for an individual
setting or additional fields may be required. Changing the number
of fields for an individual setting is within the scope of the
present disclosure. As shown in FIG. 10, there is a decrease field
1021, a value field 1022 and an increase fields 1023. As these
input fields can be replicated for each control setting 1012-1016,
only one will be described in detail for clarity of description.
The value field 1022 shows the current value for the respective
control setting, as shown in FIG. 10 brightness. On one side of
field 1022 is a decrease field 1021. On the other side of field
1022 is an increase field 1023. When the user selects the decrease
field then the value of that setting, which is shown in field 1022,
is decreased. When the user selects the increase field then the
value of that setting, which is shown in field 1022, is increased.
The fields 1021 and 1023 can be graphical buttons that are
highlighted when selected, i.e., pressed using an input device such
as a mouse or other pointing device, and change the value of the
respective control setting by one. The fields 1021 and 1023 may
further be continually selected to rapidly change the value of the
respective setting. Value field 1022 can show the absolute value of
the setting. In an alternative, the value field 1022 shows the
percent of the maximum (i.e. 0-100) for any given setting. This can
make the system easier for a student or other novice to control the
imager without learning the specifics and absolute values of
settings such as brightness, exposure, gain, frames, video size,
etc. The remote user or the fluid flow device translates the
percent settings into appropriate setting values that the imager
can understand. In the embodiment with a plurality of users, each
of the users is shown the current value of the settings in field
1022 shown on their respective remote user terminal. In an
application, only one user may change the settings. In another
application, each of the users can change the settings. This allows
the users to collaborate and possibly teach each other how changing
the settings can affect the fluid flow data that is being
acquired.
The fluid flow data preview 1030 is a display field that shows the
image data being acquired by the imager is shown to the user. The
preview 1030 includes a video presentation of the image data. The
preview can be sample of the image data. The preview can change
when the imaging control settings 1012-1016 are changed. This
graphic of the image data being shown to the user provides the user
with an essentially real-time view of fluid flow in the fluid flow
device at the obstacle. The user can change the settings of the
imager to improve the data quality.
The GUI 1000 further includes navigation links 1040 that allow a
user to navigate to different graphical user interfaces or other
modules of a fluid flow visualization/data acquisition program.
These links can include, but are not limited to acquire data and
analyze data. Other links can include end, log off, link to other
materials related to this field of study, link to class/lab
websites, link to website associated with the present system for
support or tutorials. Other links can be provided.
FIG. 11 is a visual representation of data 1100 acquired using the
system 100 described herein. The data can be displayed on a display
device such as a computer monitor or other electronic display. The
visual representation as shown in FIG. 11 is a vector field
overlaid on a frame of data. The vector field is one presentation
of data computed from the raw image data acquired by the fluid flow
device. Other data can be computed from the experimental data
acquired using the fluid flow device and the controls. Computed
data can be calculated and graphically presented to a user.
Examples of such data include streamline, voracity, shear stress,
shear strain, turbulence intensity, etc. Computation can be
performed in the analysis module 930 of the control unit 120 (FIG.
9).
The operation of the system 100 will now be described. In an
example, user must install the software or logon to the control
unit 120 to use the fluid flow device 110. A user's own computer
can be connected to the fluid flow device 110 and the software
installed from a storage media or downloaded over a network. The
software will detect the various hardware and device software and
install the proper fluid flow system software. In an example, the
user needs to merely point their web browser to the name of IP
address of the server on which the software is loaded or the DNS
name of the machine acting as the server. Thus, no software needs
to reside on the user's computer, which allows the user's computer
to be compliant with the server and use of the present invention
generally independent of the user's computer hardware or software.
Software of the present invention is then only needed for the
server and the users' computers only need functional web browser
and network connection software, which is readily available in most
notebooks/computers.
Fluid flow device 110 can now be set up for an experiment. The
window 437 in the fluid flow model insert 310 is cleaned as a
unclear window will result in poor data. The obstacle insert is
selected and placed in the recess of the intermediate member 433 of
the insert 310. The cover 435 is positioned over the intermediate
member 433 and fluidly seals this portion of the fluid flow path.
The insert is then slid into the slot in the front of the housing
301. When fully inserted, the insert 210 or 310 is releasably held
in the housing slot and activates the switch to allow the light
source 220 to be powered and the pump 205 to be fully powered.
Connectors fluidly connect the insert to fluid flow path, for
example, the tubing that is exterior to the housing as shown in
FIGS. 3 and 7. The reservoir can then be filled with a fluid. In an
example, the fluid is water. The fluid is then seeded with
particles that will be visible when illuminated by the light source
but will not impact the fluid flow. The seed particles can range in
size from 1 micron to about 100 microns depending on the density of
the transparent working fluid and Stokes number. The seed particles
can be made from nylon, polyimid, polystyrene, among others. In an
example, the particles are polyimid for density matching with the
flow medium. The particles can be coated particles to maximize the
reflected light. Particles can also be fluorescent. The particles
are placed in the fluid filled reservoir.
The fluid flow device can be connected to the control device at any
time. The fluid flow device can now be powered on. The light source
and the pump will start as the switch is on. The associated control
software or methods should be started at the control unit 120.
Images of the flow should now be displayed at the control unit. A
user at the fluid flow device can now manually slow the fluid flow
or speed the fluid flow by adjusting the knob that controls the
fluid flow resistance. In one embodiment, the flow speed can be
controlled using an electronic valve connected to and controlled by
the control unit 120. In this embodiment, the flow speed can be
manually adjusted at valve 309.
When beginning a new experiment, there may be air bubbles in the
fluid flow path. One method for removing air bubbles is squeezing
and releasing the tubing external to the housing. This moves the
bubbles within the fluid flow path and possibly moves any bubbles
to the reservoir. If the bubbles persist, then a syringe can be
connected to one of the connections and used to gently move the
bubbles. Alternatively, the syringe can be used to add fluid that
can move the air bubbles along without turning off the device 110.
In use, the syringe can pull liquid and the bubbles out of the flow
path. The gas that forms the bubbles and the liquid are separated
in the syringe. Thereafter, the liquid is injected back into the
fluid flow path. Cleaning the surface of the window 437 also
reduces the chances of air bubbles sticking to the window which can
restrict the optical path to the imager. Transparent or
semi-transparent tubing help identifying and alleviating bubble
related issues faster and easier.
The flow model insert 210 or 310 can be changed with the device 110
in operation. The fluid flow path is disconnected from the insert
210 or 310. The fluid will continue to flow to cool the light
source. The insert is removed from the slot in the housing. The
electrical control switch moves to the "off" position that places
the pump in a reduced power mode and turns the light source off.
The obstacle 800 can now be changed in the insert assembly.
The imager is controlled remotely by the control unit 120 to
acquire data from the fluid flow device 110. The user can control
many parameters of the imagers as described herein. The acquired
data can then be analyzed and used remotely from the device 110.
The control unit 110 provides a networked imager control with
essentially real-time visualization of the image data such that the
user can adjust at least the imager parameters to achieve the best
results. The control unit can connect to the fluid flow device
through any electronic network using any operating system via a web
browser.
The control unit can export the acquired data or analyze the data
for a user. The data can be exported in a plurality of formats for
additional analysis using other software. Examples of these formats
include text, png plots, post script, piv files compatible with
GPIV, an open source particle image analysis program.
FIGS. 12A and 12B show a schematic view of an application 1200 of
the present system 100 for use to provide a visual learning,
teaching or experimental tool for fluid pressure versus fluid flow.
In some embodiments of the present invention seed particles are not
required. One such embodiment is illustrated in FIGS. 12A and 12B.
Each of FIGS. 12A and 12B schematically show a portion of a flow
path 1205. This fluid flow path portion could be any portion of the
fluid flow path of the fluid flow device described herein. In one
embodiment, the fluid flow path portion shown in FIGS. 12A and 12B
is positioned at the location where the image can acquire image
data. FIG. 12A shows an application where the fluid flow path is
vertical. FIG. 12B shows an application where the fluid flow path
is horizontal. Each of FIGS. 12A and 12B includes a thin flexible
plate 1210 within the flow path 1205. In an embodiment, the plate
1210 is connected to an obstacle insert to be placed in the fluid
flow obstacle assembly and placed in the field of view of the
imager. The fluid flows in the direction of arrows 1215A and 1215B,
respectively. Referring now to FIG. 12A, the fluid flow impinges on
the surface of the plate 1210, which surface faces the inflow of
the fluid. As a result the fluid deflects the plate 1210 upwardly
away from the inflow such that the fluid can flow past the plate.
The movement of the plate 1210 is shown in broken line in FIG. 12A.
Referring now to FIG. 12B the plate 1210 is positioned loosely
adjacent one side of the path 1205. It will be recognized that the
distance from the side of the path is exaggerated for purposes of
illustration. The flow of fluid 1215B past the plate 1210 may force
the plate away from the sidewall and out into the fluid flow as
shown by the broken line in FIG. 12B. As the fluid velocity
increases, the plate 1210 will be deflected more because of the
higher pressure. However, the FIG. 12B embodiment may be
self-limiting. These embodiments can provide a further
visualization of fluid dynamics for teaching and understanding of
the complex forces in this field of study.
FIG. 13 shows a system 1300 to simulate blood flow in the present
system 100. System 1300 includes a motor 1305 to drive a cam 1310
into periodic contact with a flexible portion 1315 of the fluid
flow path. This portion of the fluid flow path 1315 can be a
flexible, transparent silicon tube to simulate a vein or artery.
The motor 1305, cam 1310 and fluid flow portion 1315 are positioned
with the housing, e.g., 301. The motor 1305 could be controlled to
drive the cam 1310 into contact with fluid flow path portion 1315
to simulate a heart beat. The fluid flow path is flexible and
resilient such that the cam 1310 deflects a portion of the path,
which in turn springs back to its normal size when the cam 1310
moves from contacting the path 1315. In another example, the cam
1310 is shaped such that its revolution movement creates the heart
beat fluid flow in the fluid flow path. In one aspect, the motor
and cam are positioned away from the obstacle insert assembly such
that the obstacle insert used could represent blockages in a
persons circulatory system. The present application is not limited
to people, the motor and cam could be controlled or selected to
mimic other animals.
In a further embodiment, the pump 205 is configured to output fluid
flow that mimics a heartbeat. The pump can produce pulsating fluid
flow at various frequencies; some of which can closely mimic a
heartbeat. A fluid that more closely mimics blood viscosity can
also be used. One example is a medium sucrose solution as the
fluid. Some of the seeding can be sized to represent cells, such as
red or white blood cellsa.
FIG. 14A show a schematic illustration of a pressure measurement
system 1400 that includes fluid flow insert assembly 1410 with
luers 1415 connected thereto. The luers 1415 fluidly connects via
fluid connections 1417, such as vias or tubes, to a pressure gauge
1420. The illustrated embodiment includes three luers with three
respective fluid connections. It is within the scope of an
embodiment of the present invention to include a single luer 1415
and fluid connection 1417. In another embodiment, any plurality of
luers 1415 and connections 1417 are provided. The flow assembly
1410 is similar to the assembly described elsewhere in the present
documents unless otherwise noted.
FIG. 14B is a top, partial view of the portion of the fluid flow
insert assembly 1400 that receives an obstacle 1425. The obstacle
1425 is shown in broken line to indicate that it is removable from
the recess 1428 in the bottom plate 1430 of the assembly 1400. A
plurality of channels 1430 are formed in the assembly extending
vertically downwardly from the top of the assembly 1400, i.e.,
vertical channel 1431, and then extending horizontally under the
bottom surface of the recess 1428, i.e., horizontal channel 1432.
An end portion 1433 of the horizontal channel 1432 is open to
apertures 1435 at an edge of an obstacle insert 1425. Referring now
to FIG. 14C, a top view of the obstacle insert 1425 for use with
the pressure measurement system 1400. The obstacle insert 1425
includes a body 805 and an obstacle 810, which can be essentially
the same as described herein but for the apertures 1435 in an edge
of the body 805. These apertures will allow the pressure in the
fluid to transmit from the fluid flow path through apertures 1435,
to channels 1431, 1432, through luers 1415 and fluid connections
1417 to a pressure sensors 1420. The pressure sensor is mounted
outside the housing of the system 110. In an embodiment, the
pressure sensor 1420 records the pressure readings and sends same
via an I/O connection to remote users.
The illustrated embodiments shown in FIGS. 14A-14C further show
that the pairs of apertures 1435 and channels 1430 are positioned
with one pair before the obstacle 810, one pair at obstacle 810,
and one pair after the obstacle 810. This allows the pressure
differences resulting from a specific obstacle insert to be
measured at three different locations. Based on these values,
Bernoulli's equation can then be calculated.
FIG. 14D shows an other embodiment of the insert 1400 including at
least two connectors 1450 that are connected to fluid apertures
that are adjacent the obstacle. These fluid obstacle can be the
same as those described above with regard to FIGS. 14A-14C. The
connectors 1450 and fluidly connected apertures are positioned to
one side of the aperture 437 such that they do not obstruct the
field of view of the imager (not shown in FIG. 14D). A portable
pressure sensor (not shown) can be connected to the connectors 1450
and be positioned external to the housing. In another embodiment,
the pressure sensor records the readings and sends same via the I/O
to the remote users and the control unit.
FIG. 15 shows a schematic view of the fluid flow device 1500 being
used to for teaching mixing flow phenomena. A portion 1510 of the
fluid flow path is outside the housing 301 and includes an
injection point 1515. The injection point can be a Tee junction or
syringe accepting point. In use, the reservoir would not be
completely filled as further liquid will be injected during
experimentation. In an example, the reservoir is about 1/2 to 3/4
full. At the injection point 1515 a liquid 1517, preferably
different than the liquid 1518 already flowing in the fluid flow
path, is injected. Both liquids 1517 and 1518 would flow into the
insert 210 wherein the imager would record the flow of the two
liquids past the imaging site. While described as two liquids, any
plurality of liquids can be used. In an example, water is flowing
in the fluid flow path. A higher density liquid, such as oil, is
injected. In a laminar flow, the two liquids would not mix.
Moreover, seed particles can be placed in each liquid and imaged
past an obstacle as well to determine mixing effects of the
obstacle. Other examples could include injection of soap into
water.
The present system 100 is ideal for the educational environment as
industrial or research particle image velocimetry (PIV) systems
typical cost round $100,000. Moreover, there are safety
considerations as these industrial PIV systems use high power
lasers, such as class IV lasers. The cost and potentially dangerous
components prohibit the use of such systems for educational
purposes. The present inventors recognized these drawbacks of the
industrial PIV systems and the need for hands on experiments to
learn fluid flow dynamics. To achieve some of these goals, the
present housing encloses all powered parts yet provides visual
evidence of the device in an operational state by allowing some
diffuse, indirect light from the light source to leak from the
housing or by images from the imager.
The present system can further record data that is later used in
qualitative and quantitative analysis, for example, in the control
unit or at remote user locations. The flow of a real fluid is very
complex and, as a result, complete solution of problems can seldom
be obtained without recourse to experiment. The present system
provides the vehicle for such experiments without the need for
expensive or dangerous equipment. Fluid mechanics is a highly
visual subject. While using the present system the user(s) can
learn about the flow qualitatively and quantitatively using
particle image velocimetry (PIV). The most common mathematical
method for flow visualization is the streamline pattern. All
visualizations can be computed at the control unit and/or the
remote user for display. Flow patterns can be described by lines
and there are several types of lines. See for example, "Mechanics
of Fluids," B. S. Massey, Chapman & Hall, ISN 0 412 34280 4 and
"Fluid Mechanics," Frank M. White, McGraw-Hill Book Company, ISBN 0
07 069673X, hereby incorporated by reference. First, Streamline:
this is an imaginary curve across which--at that instant--no fluid
is flowing. It can also be called a flowline or line of flow. At
this instant in time the direction of the velocity of every single
particle on this line is along this line. The pattern, which
several streamlines form, gives a very good description of the
flow. Since the streamlines are describing an instant of time the
patterns they form can be considered to be an instantaneous
photograph of the flow. The present system shows these
visualizations of flow when images of the particles moving fast
through the flow model are taken. Second, Pathline: An individual
particle in the flow does not necessarily follow the flow. So the
actual path that a given fluid particle follows is called a
Pathline. If one considers a streamline as an instantaneous
photograph of the flow, a pathline is time exposure of the path of
the particle at successive instants of time. Third, Streakline:
This line is the locus of particles which have passed through a
prescribed point. Another term used for this line is filament line.
Traditionally a streakline can be produced experimentally by the
continuous release of marked particles such as dye, smoke or
bubbles. In the present system streaklines are produced using solid
particles which are illuminated by a light source, such as a laser
or light emitting diode. FIGS. 19-20 are two examples of images
produced by the present system.
The present system can further provide a basis for the hands on
study of flow in ducts. There is no general analysis of fluid
motion. The reason for this is that very complex changes occur in
fluid behavior at moderate Reynolds Numbers. At this introductory
level Reynolds number is considered to be the primary parameter
affecting transition from laminar to turbulent flow.
.rho..times..times..times..mu. ##EQU00001## Where V is the average
stream velocity, p is the fluid density, p is the fluid dynamic
viscosity, and L is the characteristic length. In an example
operation of the present system water is used as the liquid. At
20.degree. C., the density and dynamic viscosity for water are 998
kg/m3 and 1.003.times.10.sup.-3 Ns/m.sup.2, respectively. In non
circular ducts, as used in an embodiment of the present system,
hydraulic diameter can be used for L. Hydraulic
Diameter=(4.times.Area)/Wetted Perimeter The value of Hydraulic
diameter in an embodiment of the present system is constant. With
the dimensions of the fluid flow path in the present system being 5
mm.times.25 mm, the hydraulic diameter is 8.33. As a result, the
following approximate ranges occur for flow in the fluid flow path:
0<Re<1: highly viscous laminar, "creeping" motion.
1<Re<10.sup.2: laminar, strong Reynolds number dependence
10.sup.2<Re<10.sup.3: laminar, boundary layer theory useful
10.sup.3<Re<10.sup.4: transition to turbulence
10.sup.4<Re<10.sup.6: turbulent, moderate Reynolds number
dependence 10.sup.6<Re<.infin.: turbulent, slight Reynolds
number dependence These values of Reynolds number a good indication
of the flow regimes, but the values can vary with surface
roughness, flow geometry, and inlet flow stream fluctuations. The
flow in the present system is considered to be internal flow
because the fluid is constrained by the bounding walls. The viscous
boundary layers grow downstream of the entrance to the portion of
the fluid flow path. This results in the retardation of the axial
flow at the wall and acceleration of the center fluid so that the
incompressible continuity law is satisfied.
In the present system, the users will be able to study flow not
only in straight ducts but also flow over obstructions by inserting
various flow model obstacles. One flow model studies the effect of
reduction in flow area on the flow. The effect can be explained by
considering the Bernoulli's equation:
P/.rho.g+u.sup.2/2g+z=Constant Where, P is pressure and z is
height. Bernoulli's equation only applies to frictionless
(inviscid), steady and constant density flows. Bernoulli's relation
is generally true only for a single streamline. The present system
can image fluid flow in a horizontal plane and hence there is no
significant gravitational effect on the flow. As a result, z can be
eliminated from the Bernoulli's equation. If we consider the flow
in a converging duct, continuity tells us that as the area gets
smaller the flow speed increases. See for example, "Mechanics of
Fluids," B. S. Massey, Chapman & Hall, ISN 0 412 34280 4 and
"Fluid Mechanics," Frank M. White, McGraw-Hill Book Company, ISBN 0
07 069673X, hereby incorporated by reference. Also Bernoulli's
equation tells us that as the speed increases pressure must
decrease. The present system can use the computing power and
systems to generate this type of data for a user.
FIG. 16 shows a schematic of an application 1600 of the present
invention, specifically, design of a fluid flow model 1610,
computational fluid dynamic analysis engine 1620, and particle
image velocimetry 1630. Such an application 1600 can be used in an
educational setting or in preliminary proof of concept in an
industrial setting to reduce costs. Design 1610 can include initial
ideas regarding a fluid flow model, such as those described herein,
which can include specific examples of fluid flow obstacles shown
in FIGS. 8A-8E. For these provided fluid flow models, a model file
can be created and stored at a remote server, e.g., server 140 in
FIG. 1. In other embodiments, a user created flow model design may
be created at 1610. This user created design is then uploaded as a
numerical representation to the CFD analysis engine 1620. CFD
analysis engine 1620 then analyzing this data based on initial
conditions and assumptions regarding the design model. In certain
cases, an assumption is made that the flow is laminar and two
dimensional grids are used of computation. Other assumptions and
initial conditions are with the scope of the present invention.
Moreover, when using the presently described fluid flow system 110,
certain boundaries and flow conditions are known and can be fixed
in the CFD analysis engine 1620. Examples of the boundaries include
the walls of fluid flow pathway in the fluid flow model. A mesh
representation of the fluid flow model is created. Various options
are available here, but for purposes of education, a
two-dimensional mesh is used. The finer the mesh, the more data
points are produced and, hence, results in more intensive and
expensive computation. It may be desirable to perform multiple
iterations on a design to efficiently develop a computational model
of the fluid flow model. Other data needed for CFD is the initial
velocities of the fluid at various points when the fluid enters the
fluid flow model. This data can be generated from data files of
previous fluid flow analysis in system 110, i.e., prior PIV runs.
The CFD engine 1620 produces data tables, graphs, or other
representations of the fluid flow model. The fluid flow model can
then be revised based on these results. The CFD engine 1620 can
thus minimize the number of physical tests that needs to be
performed during the validation process of a design. This reduces
the cost of development as physical prototypes and tests (e.g.,
PIV) are more expensive then the computational effort. The CFD
engine 1620 can produce graphics that illustrate the computational
results that can be compared to the physical data. An example of a
CFD speed flow shaded plot is shown in FIG. 21.
After computational optimization of design is achieved, then a
physical test (e.g., PIV) can be performed. A user could compare
the computational results to the PIV test results, e.g., the
immediately above graph versus previously graphs shown herein. If
the results do not agree with the CFD analysis, then the design
process 1600 repeats itself until an optimized working design is
achieved.
Once satisfied that fluid flow model meets a criteria, then the
physical fluid flow model can be used in the presently described
system 110 to generate PIV data, 1630. After the PIV data is
generated, the user can compare the physical results, e.g., the PIV
data, with the computational data from CFD engine 1620. A user can
then investigate any differences between theoretical data (CFD) and
the physical data (PIV). The process can be performed again to
achieve the desired results or to compare changes to a design.
FIG. 17 shows a flow chart of a fluid flow analysis method 1700
according to an embodiment of the present invention. At 1705, a
flow model is selected. At 1708, a determination is made whether
the model is an existing, known model. If so, then the method 1700
loads flow model data at 1709 and then moves to perform CFD at
1715. Loading the flow model data 1709 can include retrieving the
data from the server of a support system for the present invention
or the user can manually load the data. If not at 1708, then at
1710 a determination is made whether CFD was previously performed.
If not, then CFD is performed at 1715. If so, then the method 1700
moves to performing PIV using the system described herein, 1720. At
1725, the physical experimental from the PIV flow model system is
then compared to the computational data from the CFD step 1715. If
the physical data does not match the CFD data, then the user may
return to perform PIV 1720. Otherwise the method ends.
The loading of flow model data, 1709, can include the user
uploading their own model if they are working with a custom one.
The user can further select various options pertaining grid
generation, which is used in CFD. For existing models, a number of
grids may already be generated. Otherwise, the user enters boundary
conditions manually. In an alternate embodiment, the boundary
conditions are determined from previous PIV data.
Performing CFD, 1715, can include producing graphs and images (e.g.
velocity vector field, velocity magnitude graphs) that are
equivalent to graphs and images that are produced by PIV using the
present system.
Comparing PIV results with the corresponding CFD results, 1725, can
include comparing the raw data, graphs, images, or combinations
thereof. The user should be able to explain how well they match, or
if they do not match, try to explain why it did not match. Based on
this comparison, the user should be able to go back and reiterate
to more closely match the data or see how changes to the PIV test
equipment or data input into the CFD step may change results.
The present system(s) and method(s) should assist a user in
analysis of experiments, including but not limited to,
quantitatively generate a velocity vector field, plot data in
graphical format with label and units of variables, e.g. shaded
plot, extract data from the results and plot in linear graphical
form, e.g. velocity versus location, calculate the average flow
rate at a particular cross section, understand variability in
experimental results, export velocity data into Excel or another
analysis software to perform further calculations, e.g. calculate
vorticity.
The present system(s) and method(s) should assist a user in
understanding fluids concepts, such as laminar flow, turbulent
flow, Reynolds number, boundary layer, shear layer, strain rates,
shear rate, streamlines, vorticity, viscosity, flow separation,
continuity, recirculation, flow acceleration and deceleration. When
multiple flow models are supplied with the fluid flow device, the
user will also be assisted in understanding the various flow
phenomena observed in the flow models supplied with the system, how
to design custom flow models to create custom case studies, how to
follow the design optimization process (FIG. 16), research skills
including using a professional laboratory notebook, the importance
of keeping accurate records, reading the manual and following
operating instructions, changing the seeding density incrementally
and observing the PIV results, following the sequential process of
removing bubbles--if any--as per the instruction manual, recording
PIV data for further analysis and report writing, ability to vary
the flow rate and direction, ability to interchange the flow
models, and a use of present software and hardware, and optimizing
PIV parameters.
The above Detailed Description is intended to be illustrative, and
not restrictive. Accordingly, the various embodiments described
herein may be implemented with software, firmware, or hardware. The
various embodiments are not necessarily mutually exclusive, as some
embodiments can be combined with one or more other embodiments to
form new embodiments. For example, the above-described embodiments
(and/or aspects thereof) embodiments may be combined, utilized and
derived therefrom, such that structural and logical substitutions
and changes may be made without departing from the scope of this
disclosure. Such embodiments of the inventive subject matter may be
referred to herein, individually and/or collectively, by the term
"invention" merely for convenience and without intending to
voluntarily limit the scope of this application to any single
invention or inventive concept if more than one is in fact
disclosed. Many other embodiments will be apparent to those of
skill in the art upon reviewing the above description. The scope of
the invention should, therefore, be determined with reference to
the appended claims, along with the full scope of equivalents to
which such claims are entitled.
Other embodiments will be apparent to those of skill in the art
upon reviewing the above description. The scope of the invention
should, therefore, be determined with reference to the appended
claims, along with the full scope of equivalents to which such
claims are entitled. In the appended claims, the terms "including"
and "in which" are used as the plain-English equivalents of the
respective terms "comprising" and "wherein." Also, in the following
claims, the terms "including" and "comprising" are open-ended, that
is, a system, device, article, or process that includes elements in
addition to those listed after such a term in a claim are still
deemed to fall within the scope of that claim. Moreover, in the
following claims, the terms "first," "second," and "third," etc.
are used merely as labels, and are not intended to impose numerical
requirements on their objects.
The Abstract is provided to comply with 37 C.F.R. .sctn.1.72(b),
which requires that it allow the reader to quickly ascertain the
nature of the technical disclosure. It is submitted with the
understanding that it will not be used to interpret or limit the
scope or meaning of the claims. Also, in the above Detailed
Description, various features may be grouped together to streamline
the disclosure. This should not be interpreted as intending that an
unclaimed disclosed feature is essential to any claim. Rather,
inventive subject matter may lie in less than all features of a
particular disclosed embodiment. Thus, the following claims are
hereby incorporated into the Detailed Description, with each claim
standing on its own as a separate embodiment.
* * * * *